Pot size: Yes, (the right) size matters!

These articles are extracted from the Yuruga Newsletter
Vol 13 No 1
(December 2005).

Traditionally, native plants are sold in two pot sizes: tubes and 140mm pots.

Tubes, being smaller, are cheaper to buy and easier to plant than pots, and so are quite an attractive proposition for gardeners. So why do we here at Yuruga Nursery sell most of our plants in 140mm pots and not in tubes?

We can hear the cynical amongst you say “To make more money, of course!”, but no, that’s not the reason and actually, the profit margin on pots is less than on tubes. It’s because the survival and growth of the plants our customers buy is of utmost importance to us, and to put it simply, pots in general have a much higher survival, establishment and growth rate than tubes.

This is because young plants are like young people – they need to be big enough, strong enough and well-developed enough before they can be sent out into the world to fend for themselves on their own. Just as a two-year old child is not big enough for school, young plants in tubes are, in general, not well-enough developed for planting out until they reach the 140mm pot size.

It is false economics to buy smaller, cheaper plants in tubes if they either fail to grow and thrive, or worse still if they die, since you will have to spend more money replacing them, and quite possibly end up spending more in total than if you had bought 140mm pots in the first place.

Sometimes when comparing a plant in a tube with a plant in a pot, you may find that the height of the plant looks much the same, so why pay more for a pot when you can get (apparently) the same size plant in a tube? Answer: Because the root system in the tube is much smaller than the root system in the pot, and it’s the root system which powers the plant and which largely determines whether the plant survives and grows during those vital first few months.

Here’s a few statistics. The average survival rate of plants planted from pots is 99%. The survival rate from tubes varies considerably, but is rarely over 90% and often 50% or even lower. Furthermore, gardens planted from pots ‘take off’ quickly and have a mature look within two years. In comparison, gardens planted from tubes ‘take off’ much slower and it is usually at least three years before good results are evident.

Interestingly though, it’s not a case of ‘the bigger the better’. Gardens planted from larger pots (eg 200mm pots and advanced plants in 25 litre bags) actually take longer to establish than gardens planted from 140mm pots, which grow faster and often overtake the larger plants which, of course, cost more to buy. So, weighing it all up from every angle the 140mm pot is the most cost-effective size and this is why it is the standard size sold by professional nurseries.

So, getting back to tubes, Yuruga Nursery is very fussy when it comes to selling tubestock. We take great care to offer for general sale only those species of plants which we know have a very good chance of surviving and growing from tubes (eg eucalypts, acacias and casuarinas). You’ll see these listed on our stock list each month.

Rules are made for breaking, of course, and we will sell tubes of a wider range of species provided we are confident that the circumstances are such that they will have a high chance of survival. Examples include high rainfall areas such as Tully, and large scale plantings such as timber plots where the landholder is prepared to put in intensive care in the early stages to ensure survival. Talk to us about your individual situation.

So, the moral of the story is this:

Tubes are cheaper to buy than pots because they are smaller. However, what you save in money, you must be prepared to invest in additional care and nurturing, otherwise your plants will not grow and you will have wasted your money altogether.

For more information about this subject, see our Yuruga Information Sheet “Caring for plants in tubes“.